At present, every large oil field vigorously promotes the mining technology for horizontal wells by focusing on improving the reservoir utilization, improving the recovery, improving single well output, and reducing the mining cost. However, since the trajectory of the borehole and the well pattern for injection production is complex and changeable, and the reservoir lithology, physical properties and reservoir fluid properties of each oil layer also differ from each other, each layer section of the horizontal well is different in the water absorption capacity, water line speed, and liquid production, resulting in that some layer sections of the horizontal well has earlier water breakthrough, and the position and direction of the water breakthrough, and the productivity and pressure condition of each layer section is not clear. At present, since the test technology for horizontal well is not mature enough, in particular, the test technology of horizontal well of low permeability reservoir which has low liquid level is still in the stage of exploration, resulting in that measurement for dynamic adjustment in site is pointless, and seriously affects the horizontal well development effect.
Thus, the operation of horizontal wells generally requires three stages, namely, testing, communicating and producing. During the testing process, a test tubular column needs to be placed to obtain the testing data; when transmitting the testing data from underground, a communication tubular column needs to be placed, and when performing ordinary production, the test tubular column needs to be pulled out and then a production tubular is placed.